Brush-holder for electrical machines.



No. 825,974. PATENTED JULY 17, 1906.

0. B. MILLS.

BRUSH HOLDER FOR ELECTRICAL MACHINES. APPLICATION FILED 0013,1904.

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TORNEY UNITED STATES PATENT OFFICE.

CHESTER B. MILLS, OF WILMERDING, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A COR- PORATION OF PENNSYLVANIA.

BRUSH-HOLDER FOR ELECTRICAL MACHINES- Specification of Letters Patent.

Patented July 1'7, 1906.

To all whom it may concern:

Be it known that I, Cnnsrnn B. MrLLs, a citizen of the United States, and a resident of WVilmerding, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Brush-Holders for Electrical Machines, of which the following is a specification.

My invention relates to electrical machines, and particularly to brush-holders and brush-holder brackets for such machines.

The object of my invention is to provide brush-holders and brush-holder brackets of such construction and arrangement that the holders may be readily adjusted upon the brackets to adapt them to commutator-cylinders of different diameters.

In the construction of an electrical machine having a commutator which embodies carbon-brushes it is very desirable, if not absolutely necessary, to so construct and arrange the brush-holders and their supporting-brackets that the brushes shall be disposed at suitable angles to the planes which are tangent to the commutatoncylinder in order that satisfactory operation. may be insured. In order to effect this arrangement of parts, it has heretofore been found necessary to design a brush-holder for each size of machine, thus necessitating a large number of patterns, and therefore materially increasing the cost of the machines beyond what would be involved if a single design of brush-holder could be utilized in connection with machines of different sizes.

In the accompanying drawings, Figure 1 is a View, partially in end. elevation and partially in section, of a brush-holder and a portion of its supporting-bracket constructed in accordance with my invention. Fig. 2 is a plan view, and Fig. 3 a side elevation, of the brush-holder shown in Fig. 1. Fig. 4 is a side elevation of a portion of one of the brush-holder brackets and portions of a set of brushes supported thereby.

In the construction of machines of considerable size it is usual to provide each bracketarm with a series of alined brush-holders each of which has a carbon-brush that is independently pressed against the commutator-cylinder by a suitable spring, and this is the type of construction which is illustrated in the drawings. So far as my present invention is concerned, however, it is immaterial whether the bracket is provided with one or with a plurality of brush-holders, and for simplicity and convenience of description the invention will be hereinafter described for the most part as if each bracket were provided with one brush-holder only.

As shown in the drawings, the brushholder 1 is provided with a socket 2, in which is mounted a carbon-brush 3, the inner end of which bears upon the commutator-cylinder 4 and the outer end of which is provided with a metal yoke 5, that is clamped to the brush by means of a bolt 6 and a split washer 7. A strap-metal shunt 7 is connected at one end to the brush by means of the bolt 6 and at its other end to the brush-holder casting by means of a thumb-nut 8.

The brush 3 is pressed against the commutator-cylinder 4 by means of an arm 9 and a spiral spring 10, that are riveted together, as indicated at 11. The pressure exerted by the spring 10, and consequently the force exerted by the arm 9, upon the brush 3 may be adjusted by means of an arm 12, that projects from the shaft 13, to which the inner end of the spring 10 is fastened. The casting 1 is provided with a series of notches 14, in any one of which the arm 12 may be seated in order to insure the desired adjustment of the spring.

The features thus far described do not pertain to my present invention except in the sense and to the extent that they are features of an operative brush-holder structure, and they may therefore be replaced by other devices which will perform the necessary functions, if desired.

The bracket 15 for supporting the brushholder above described is provided at each side adjacent to its inner edge with longitudinal recesses 16, the cross-sectional curvature of which conforms to the arc of a circle, and the adjacent end 17 of the brush-holder 1 is provided with a semicylindrical portion 18, the radius of curvature of which is the same as that of each of the recesses 16.

The brush-holder end 17 having the curved portion 18 is bored to receive a cylindrical block or pin 19, the fit between these parts being such that the holder may turn upon the block when desired for adjustment purposes. The block 19 is provided with a screw-threaded transverse hole 20, which receives the inner end of a bolt 21. The bolt 21 projects through an opening in the bracket 15 and is provided with a nut 22 for clamping the brush-holder to the bracket.

The portion '18 of the brush-holder is provided with a recess 28, the length of" which is materially greater than the diameter of the clamping-bolt 21 in order that the holder may be adjusted to adapt it to the commutator-cylinder in connection with which it is to be used when the clamping-bolt is loosened. After the desired adjustment is effected the block 19 may be securely clamped in position in its socket by means of a setscrew 24.

It will be seen from the illustration and the foregoing description that the brush-holder may be clamped to either side of the bracket and may be angularly adjusted thereon to the extent desired in order to accommodate the structure to a specified diameter of commutator-cylinder and that when so adjusted the holder may be readily and securely clamped in the proper operative position.

Variations in the structural details may of course be made without departing from my invention.

I claim as my invention 1. In an electric machine, the combination with a brush-holder bracket and a brushholder having cooperative means for right or left location of the holder and for adjustment of the holder on the bracket toward and away from the commutator-cylinder, of means for clamping said holder in any position to which it may be adjusted on the bracket.

2. In an electrical machine, the combination with a supporting-bracket having two oppositelydisposed, curved recesses, of a brush-holder having a curved projection that may be adjustably seated in either of said recesses, and means for clamping said parts together.

3. In an electrical machine, the combination with a supporting-bracket having two oppositely-(lisposed, longitudinal recesses of arc shape in cross-section, of a brush-holder having a projection the curvature of which is the same as that of said recesses, and means for clamping said projection in either of said recesses to provide any desired angular rela tion between the bracket and the brush- 5 5 holder.

4. In an electrical machine, the combination with a supporting-bracket having two oppositelydisposed, longitudinal, curved recesses, of a brush-holder having a projection that may be seated in. either of said recesses and be rotatively adjustable therein, and means for clamping said brush-holder in any position to which it may be angularly adjusted.

5. In an electrical machine, the combination with a supporting-bracket having a longitudinalreoess having the form of a cylindersegment, of a brush-holder having a projection in the form of a cylinder-segment the radius of curvature of which is the same as that of said recess and having a concentric bore and a lateral opening, a cylindrical block seated in said bore, and a clampingbolt that projects through the lateral opening and into said cylindrical block and also through the supporting-bracket.

6. The combination with a supportingbracket provided with a longitudinal recess having the form of a cylinder-segment, of a brush-holder having a semicylindrical projection provided with a concentric bore and a lateralopening, a block located in said bore, a clamping-bolt projecting from said bracket through the lateral opening and into the said block and means for locking said block against rotative movement.

7. The combination with a supporting bracket having opposite, longitudinal, curved recesses, a brush-holder having a projection of such form as to fit into either of said recesses and thus permit of angular adjustment of said holder, and means for clamping the holder in any position to which it may be adjusted.

S. The combination with a supportingbracket having a longitudinal, curved recess in each side thereof, of a plurality of brushholders severally provided with curved proj ections that are adjustably seated in the one or the other of" said recesses, and means for clamping said projections in said recess in accordance with the angle to which the holder may be adjusted.

In testimony whereof I have hereunto subscribed my name this 12th day of September, 1904:.

CHESTER B. MILLS.

Witnesses:

1311mm IIINES. J. C. Monsn. 

